Magnetic separator



Juiy 17, 1923.

A. F. JOBKE MAGNETIC SEPARATOR Original Filed April 24, 1918 Patented Ju1 i7, 1923.

: UNITED STATES.

} 1,462,111" PATENT. OFFICE.)

nueusrr. JO'IBKE, OFLII'I'TSBURGH, PENNSYLVANIA.

MAGNETIC snrnnn'ron.

Division after grant of application Serial No.' 230 ,604, filed April 24, 1918. "This application filed May 2a, 1922. Serial No. 564,576. a 1 i T all whom it may concern.

Be itknown that I, AUGUST F J OBKE, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and 5 State'of Pennsylvania, have. invented an Improvement in Magnetic Separators, of which the following is a specification.-

My invention relates to improvements in magnetic separators,r particularly to the W means forming the magnetic separating fields and the separating members, and its object is an increase of the workingcapacity of a magnetic separator and a separating member of low reluctance and freedom from induct-ion currents due to-itsmovement in a strong magnetic field.

In U. S. Patent 1,346,544 there is a separating member described and specified, which is arranged on a radiusto the axis of its movement, and the advantage of its form and position in the magnetic field shown. The present inventionmakes use of asimilar member and field arrangement, but .de-

viates from the cited arrangement in that theseparating member is-placed at an angle to the radius, thereby providing certain advantages, which'will be brought out in the following description, where reference is had to the accompanying drawing, in which:

Figure l is a sectional view showing a magnet-field formed by an upper and lower magnet-pole with an air-gap of varying lengths and traversed by a separating member rotating about a vertical axis and nor- 3 shows a fractional plane view of a spider carrying a determined number of separating members at its rim. Figure 3 shows a similar view, having the separating members at 40 an angle varying with the length of the radius, i. e., curved. Figures 4L and 5 aretwo sectional views ofthe separating members adapted to vary the forms of the soparating-field to suit varying requirements. Figure 6 is a sectional view of the field formed by upper and lower magnet poles andfa separating member, the arrangement providing for a distinct separation of the magnetic field into three zones of different strengths, and Figure'7 is a sectional View 66 terline of motion, their number is made an mally to the direction'of the flux. Figurefl,

even one, and the lines of force of each-field are directed oppositely to those of the neighboring ones, thus providing for a reversal of the magnetizationof the separating members in passing from one field to the next one.

ing the pole 1, and the pole 2 is advanta geously connected magnetically with the up .per poles of the neighboring magnet-fields, the return-circuit being made through their mension should be sufiicientlyasmall, to sup Each field is formed by a lowernpole, 1 and an upper pole 2, Figure 1; "A magnetizlng coi13 is arranged on a core carry-- press the eddy currents due to the motion in a magnetic field, which would beset'up in planes at right angles to the flux. A temporary magnet of such form and magnetized as here state'd has a very high factor of demagnetization, which is ofv great importance in the performance of the magnetic separator, in that it permits the ready release of the'ore particles upon leaving the magnet-field. Dynamic currents, the path of which will be in a radial direction, will be successfully suppressed, ifthe members are mounted with an air space between them andtheir'ends isolated from one another.

-The separating members 5 are arranged over an oreconv'eyor 4 with the necessary clearance to permit the'ore to travel freely,

while the conveyor may bearranged closely They are preferably made of the softest iron of a high permeability, in order to become 1 atan angle to a radius from the axis, around WhlClI they revolve, as shown in Figure 2.

highly magnetized in the magnet-fields. Their support, the spider 6, arranged to be revolved with a uniform speed about a vertical axis, is to be made of non-magnetic material, and various means may be employed to fasten the separating members to the same. for example casting them in or clamping them at their dove-tailed ends.

In passing through a magnet-field, members 5 become highly magnetized, and the flux density in them is higher than that on the pole-faces, due to the air spaces between them, which are voided of flux on account of the higher permeability of the iron members. Their lower side, having a wedgeshaped edge, concentrates the magnetic flux to a maximum, and magnetic particles will therefore be readily attracted to the same; Their vertical dimension being relatively short, the members will, upon leaving the field, immediately lose their magnetism, i. e., demagnetize themselves, and drop the con" centrate in the space between adjacent fields.

Upon approaching the next field the direction of the flux through the members 5 is gradually reversed due to the existing stray field, and any ore particles clinging to the edges through. their permanent magnetism, will now be repelled. The separating mem here are then ready to repeat their performance in the next field.

Owing to the position at an angle to a radius of the separating members 5, there is a difference in performance at different velocities of the same and more so at different directions of velocities. Suppose the separating members are revolved in a clockwise direction, viewing Figure 2, the ore feed being assumed to be radially inward. De-

pending on the speed of the ore, the collect-' ing edge of the separating member can be made to follow an ore particle more or less during its travel through the field, or the particle, upon entering the field, may be under the influence of one separating member and upon leaving under the edge of the following member, in both cases having a maximum time in its exposure to the magnetic action of at least one member, and therefore the best opportunityv to disengage itself from entangling non-magnetic matter.

If the conveyor 4 is of the vibratory type, it may be assumed, that every particle at any time is free to follow the magnetic attraction, and in this case it is of advantage, to rotate the separating members 5 in a counter clockwise direction. In its travel through the ma netic field every part of the ore charge wouId then be subjectedto the influence of several separating edges in succession, but, if picked up immediately, more actual length of bare separating edge is presented. Therefore a quicker separation takesplace, and the ore-feed can be increased.

In Figure 3 the separating members 5 are of different lengths on both the upper and lower pole in stepping off the pole shoes '7 and 8. The flux density through the members 5 then varies according to the reluctance of the circuit through the different airgaps. In Figure 7 the same object is attained with gaps of equal len ths by providing separate magnetic pole pieces 9 and 10,

which are energized through the straying flux between poles l and 2. Since they are magnetically separated from the main poles l and 2, the air gaps between them are the factors determining the strengths of flux through the separating members 5.

The separating members are shown as being clamped to the spider with the interposition of insulation 11, which insulates the members from the spider 6 as well as from one another. Through this arrangement galvanic currents will be prevented, which would arise between the alloy of the spider and the iron of the separating memher, if wet separation were undertaken.

Having thus described my invention, what I claim is: i

- 1..In a magnetic separator a separating member movable between upper and lower magnet poles, having its largest dimension and a. lower collecting edge at an angle to the direction of the flow of ore and to a radius from the axis of its movement,and its smallest dimension in a direction at right angle thereto and to the flux and in the direction of its movement.

2. In a magnetic separator a separating member movable between upper and lower magnet poles, having its largest dimension and a'lower collecting edge at an angle to the direction of the flow of ore and to a radius from the axis of its movement, the angle varying with the length of this radius, and its smallest dimension ina direction at right angle'thereto and to the flux and in the di rection of its movement.

3. In a. magnetic separator a separating member movable between upper and lower magnet-poles, having its largest dimension and a lower collecting edge at an angle to the direction of the flow of ore and to a radius from the axis of its movement, and its smallest dimension in a directionat right angle thereto and tothe flux and in the direction of its movement, its one end being isolated from. an adjacent separating member.

42. In a magnetic separator a separating member movable between upper and lower member.

5. In a magnetic separator a separating member movable between upper and "lower magnet-poles having its largest dimension and a lower collecting edge at an angle to b the flow of ore and to a radius from the axis v of its movement and its smallest dimension at right angle thereto and to the flux and in the direction of its movement, and a conveyor between the separating member and a lower magnet-pole.

6. In a magnetic separator a. separating member movable between upper and lower magnet-poles having its largest dimension and a lower collecting edge at an angle to the flow of ore and to a radius from the axis of its movement, the angle varying with the length of this radius, and its smallest dimension at right angle thereto and to the flux and in the direction of its movement, and a conveyor between the separating member and a lower magnet-pole. 7. In a magnetic separator substantially vertical magnet-poles of alternately oppo-e site directions formedby upper and lower poles located on a circle, having zonal airgaps of uniform but increasing strength, due to decreased reluctance in the circuits through the several Zones in the direction of the ore flow,-electrically insulated separating members, extending with their largestdimension and a lower collecting edge in a direction at an angle, to a radius of a spider supporting oneend or the said members, the movement of the separatingmembers being at right angle to the flow of ore and to the flow of flux, and a conveyor between the lower poles and the separating members, parallel with the latter.

8. In a magneticseparator, substantially vertical magnet-poles of alternately opposite directions rormed by upper and lower poles located on a circle, having Zonal air-v gaps of uniform but increasing strength, due to decreased reluctance in the circuits through the several zones in the direction of the'ore flow, electrically insulated separat ing members, extending with their largest dimension and a lower collecting edge in a direction at an angle to a radius of a spider supporting one end of the said members, the angle varying with the length of the said radius and the moven'ient'ot the separating members being at right angle to the flow of oreand to the flow offlux, and a conveyor between the lower poles and the separating members, parallel with the latter.

In testimony whereof I aflix my signature.

AUGUST r. Jones. 

